Solenoid structure



Feb. 23, 1965 D. c. SHERRICK SOLENOID STRUCTURE 2 Sheets-Sheet 1 Original Filed Dec. 13, 1956 Sm QM United States Patent Oflice 3,170,988 Patented Feb. 23, 1965 3,170,988 SOLENOID STRUCTURE David C. Sherrick, Bethesda, Md., assignor to SCM Corporation, a corporation of New York Original application Dec. 13, 1956, Ser. No. 628,110, new Patent No. 2,982,810, dated May 2, 1961. Divided and this application Apr. 11, 1961, Ser. No. 102,259 11 Claims. (Cl. 178-28) This invention relates to solenoid structure utilized in printing telegraph receiving and selecting mechanism and has particular reference to two-position solenoids with magnetic detention in both positions. This application is a division from co-pending application Serial No. 628,110, filed December 13, 1956, now Patent No. 2,982,810.

With the increasing use of interofiice telegraphy and integrated data processing systems, it is advantageous to transmit the units of a code group in simultaneous form over a plurality of wires. By using simultaneous transmission, less complex and higher speed translators can be used at the various receiving machines. This invention involves a bank of two-position solenoids, each solenoid being capable of a high speed shift to either of two positions in response to specific electrical impulse signals of extremely short duration, e.g., two milliseconds, and in either position the solenoid plunger will be magnetically locked by hysteresis flux.

The structure disclosed in parent application Serial No. 628,110 includes keyboard transmitting equipment that can transmit the units of a code in sequential arrangement and simultaneous arrangement and a receiver which utilizes the present invention in translating mechanism capable of receiving and translating either form of signals, sequential or simultaneous, to a mechanical code signal condition. This present invention is directed to the solenoid construction, per se, but reference is made to a receiver mechanism for purposes of showing an example of utility and, to this end if more specific details of the receiving mechanism are necessary, reference may be made to aforenoted co-pending application Serial No. 628,110 or to co-pending application Serial No. 92,503, filed March 1, 1961, both applications disclosing but not claiming the solenoid construction of this invention.

Accordingly, a primary object of this invention resides in the provision of a novel solenoid construction with a two-position plunger.

Another object resides in the provision of magnetic flux detents for each position of the solenoid plunger in a two-position solenoid.

A still further object resides in the provision of a unitary solenoid structure with multiple two-position solenoid plungers. In conjunction with this object it is a further novel object to provide each solenoid with two control coils and provide independent control of all coils. In further conjunction with the novel multiple solenoid structure it is a further object to include magnetic detents for each end position of each solenoid plunger.

Further novel features and other objects of this invention will become apparent from the following detailed description, discussion and the appended claims taken in conjunction with the accompanying drawings showing preferred structures and embodiments, in which:

FIGURE 1 is an elevation view illustrating various units of a sequential and simultaneous receiving and selecting mechanism of a printing reperforator utilizing the multiple plunger solenoid unit of this invention;

FIGURE 2 is a perspective view, partially cut away, illustrating the unitary solenoid structure and Y-levers of the simultaneous receiver;

FIGURE 3 is a section view through the solenoid upper block taken on line 33 of FIGURE 2 and illustrates the position relationship of the solenoid plunger bores and the central bore for the lead-in wires to the solenoid coils; and

FIGURE 4 is a schematic vertical section through the unitary solenoid structure illustrating the magnetic circuits of the simultaneous receiver and used in the description of the magnetic detent action for each plunger position.

General Description The solenoid structure will be described in a general sense in connection with a telegraphic receiving and selector mechanism. The sequential receiver of the perforator includes a conventional single relay receiver with selecting levers, Y-levers and transfer T-levers similar to receiving structure shown in Patent No. 2,773,931. The sequential receiver cooperates with associated mechanism to translate the incoming sequential pulses into simultaneous switch positions which in turn operate the simultaneous receiver portion of the perforator. This latter portion includes the multiple solenoid bank.

The receiver will receive a telegraph message from a wire and translate the electrical code signals into mechanical operations to type the message on a paper tape and at the same time record the code in the tape by means of punched holes. A reperforator of the nature referred to is disclosed in United States application Serial No. 472,076, filed November 30, 1954, now Patent No. 3,014,095, December 19, 1961, to which reference may be made for details of typewheel, printing and perforating mechanism, not illustrated herein. In order to mechanically utilize the electrical form of the received code signals, the elements of the code must be converted into mechanical settings. US. Patent No. 2,754,361 discloses a selector for this purpose, components of which are employed as subcomponents in the receiver. A very brief description of the sequential selector of this device and its operation will now be given.

All of the receiving selector mechanism, both sequential and simultaneous, will' be located at one side of a reperforator and single units of the essential multiple elements are shown in FIGURE 1. To receive sequential signals to be converted to mechanical settings, there is a selector magnet 244 with a movable armature 246. The winding of selector magnet 244 receives the sequential electrical pulses of the code combination and armature 246 is caused to move to one of two positions, depending on whether the impulse received is a marking or a spacing impulse. Each of the five electrical impulses that comprise any code combination group is recorded in the form of clockwise or counterclockwise movement of five corresponding Y-levers 248. This is accomplished through the use of five selector cam lobes 250 operating in conjunction with five selector levers 252 and the armature 246. The five Y-levers 248 are mounted on a common pivot stud 254, the five selector levers 252 are mounted on a pivot stud 256 and the five selector cam lobes 250 are mounted in axially spaced relation on a rotatable camshaft 258 with the cam lobes projecting at progressively offset angles from the camshaft 258. One selector cam lobe 250 operates in conjunction with only one associated selector lever 252 and that lever with only one associated Y-lever 248. Thus there are five planes, one in back of the other, each containing a set of these three parts. The end 260 of the selector magnet armature 246 is broad enough to engage all five selector levers. Each of these five sets of parts records one of the impulses of the five unit code. The first set records the first impulse, the second set the second impulse, etc.

During the time a markingimpulse is received, the selector magnet armature blade 26% is moved into the path of a selector lever 252. Near the middle of this time period, the selector cam lobe 250 corresponding to the impulse being received will be rotating, will engage and raise the selector lever 252. As the armature blade 2:50, being positioned in the path of a selector lever 252, prevents raising of the right end of the selector lever, the selector lever is forced to rise at its left end by sliding on the bearing shoe 262. In so doing, the selector lever 252 pushes against the Y-lever 248 at its end 264, turning the-Y-lever clockwise (unless it is already in that position). Further rotation of the selector canishaft 258 permits the selector lever 252 to drop back, but the Y-lever 248 is held in the clockwise position by a detent 266. A marking impulse is thus recorded in the form of the clockwise position of a Y-lever;

During the time a spacing impulse is received, the selector magnet armature blade 260'is moved away from the selector levers 252. Near the middle of this time period, the rotating selector cam-lobe 258 corresponding to the impulse being'received will engage and raise the corresponding selector lever 252.. The end 2600f the armature does not-obstruct the right-hand end of the selector lever 252, therefore the right-hand end is free to rise. In rising, the right-hand end of the selector lever 252 pushes up against the end 268 of the Y-lever 243, turning the Y-lever counterclockwise (unless it is already in that position). A spacing impulse is thus recorded in the form of the counterclockwise position of a Y-lever. The Y-lever detent 266 also holds the Y-lever in the space position.

To synchronize the selector cam lobes 259 with the incoming electrical impulses, cam lobes 254) are set into motion from a stopped position-at the start of each code.

group and stopped at the end of each code group. The selector camshaft 253 is driven by a drive shaft (not shown) through a friction clutch. Normally when no messages are being received, current flows in the windings of the selector magnet 244 and the camshaft 258 is prevented from turning by the interoperation of the selector magnet armature blade end 26%, step lever 274, and a camshaft stop plate 276. When moved to the left, the armature blade end 26% engages the stop lever 274 which in turn prevents the stop plate 275 and selector camshaft 258 from turning. When the start (nocurrent) impulse for a code group is received, the armature end 260 is moved to disengage the stop lever 2'74, releasing itand the stop plate 276; the selector camshaft 258 immediately starts to rotate, bringing the first selector cam lobe 251) into engagement with its selector lever 252 by the time the next impulse of the code group (first bit) is received.

Thereafter each of the remaining five selector cam lobes strikes its respective selector lever when the corresponding code bit is being received. All five cam lobes operate their selector levers within one half revolu tion of the camshaft. The camshaft is limited to making only one half revolution per code group because, after the last five bit impulses are received, the stop impulse moves the magnet armature 246 to the left to en gage the stop lever 274. plate 276, which then comes around, engages and is held by the stop lever 274 to stop the camshaft 253. If further details of the. sequential receiving structure is desired, reference is made to U.S. Patent No. 2,754,361.

Five dielectric code plates 280 (only one being shown) of a code actuated switch must be positioned according to the incoming sequential code group in order to convertthe received sequential form of the code group to a simultaneous form to be received by five solenoids for subsequent conversion to a printed message and punched tape. the Y-levers 248 by clockwise and counterclockwise set- The other end of the stop The incoming code group, as stored in tings, is transferred to the dielectric code plates 280 by mechanism to be now described.

Each code plate 239, at its lower end, carries a slotted metallic shoe 282 which mates with a corresponding tail 2% of one of five T-levers 286..(only one being shown), all of which are mounted ona common pivot 283 carried on the end of a transfer lever 290. The five code plates 280 are mounted for reciprocation on two fixed posts 233 and 285 which pass through appropriate slots.

can engage one end of a Y-lever at any time and the ends which engage will depend upon Y-lever position. When the transfer operation takes place, the transfer lever 290 moves all of the T-levers against the Y-levers and the T-levers assume positions corresponding to associated Y-levers, thus transferring the five stored code settings of the- Y-levers to the T-levers and thence to the code plates 2%.

The transfer operation, a reciprocatory swinging movement of the, transfer lever 2%, takes place after the fifth code bit is stored in the Y-levers but before the selector camshaft 258 is brought to rest by the stop signal. A transfer lever latch tripping cam (not shown) mounted on the selector camshaft 258, trips a transfer lever trip latch 3&2 which holds transfer lever 29th in a left-hand position, and the transfer lever 290 is pulled clockwise by the transfer lever spring 304. The timing of the latch tripping cam 300 with respect to the five selector cams 250 and stop plate 274 is such that the tripping action takes place only after the Y-lever selecting operation is completed and before the selector camshaft 258 is stopped.

Each of the five code plates 289 is associated with one of five contact wipers 3&8, each of which is disposed in a cut-out 31-9 in the upper end of one code plate. Each wiper 3% slides within a slot in a guide block 322, one slot being provided for each wiper. Guide block 322 is fastened to a switch plate 324 by screws 326.

The switch plate 324 includes a printed circuit with contact strips (not shown) which provide the common contacts of the simultaneous circuit, the printed circuit also providing two morecontacts for each contact wiper. Each of these contacts has printed circuits which terminate at pins connecting to the solenoid bank through the bundle of'leads shown at the top of FIGURE 2. Details of the circuits are disclosed in parent application Serial No. 628,110 and are not necessary for the present disclosure. Thus when a code plate 286 is in the upper position (spacing), the lower arm of the wiper 308 rides against'the lower common contact strip while the upper arm 312 rides against its associated contact, closing one c1rcuit to a solenoid of the simultaneous selecting mechanism. In this manner, each code plate 280'closes onecircuit if the impulse it represents is a marking impulse, or closes a different circuit if the impulse it represents is a spacing impulse.

A code actuated switch function shaft 350, FIGURE 1, performs three main functions: (1) it restores the transfer lever 290 and associated mechanism to its latched position, (2) it provides power to register and lock the code-plates 280m place and (3) it controls a switch which energizes the circuits of-the simultaneous receiving mechanrsnr.

Function shaft 350 is driven in a counterclockwise direction through a toothed clutch at the right-hand end of the shaft. operation takes place and the function shaft 350 starts The clutch is engaged when the transfer to rotate. The T-levers 286 must be moved away from the Y-levcrs before the next code group can be set up in the Y-levers and this action is accomplished when the transfer lever 290 is restored to the latched position. The transfer lever 290 must be rotated slightly counterclockwise against the tension of the spring 304 and latched in this position by the transfer lever latch 302. A cam 362 at the left-hand end of the function shaft 350 operating on a roller 364, mounted on an extension arm of transfer lever 290, accomplishes this restoring action during a onehalf revolution of the shaft 350 by camming the transfer lever 290 toward the restored position. Near the end of the one-half revolution, as the transfer lever moves into restored position, the transfer lever latch spring 366 pulls the transfer lever latch 302 into position to latch the transfer lever.

After the five code bits have been received by the sequential receiver and the associated selector mechanism has caused the positioning of the five code plates 280, the plates 280 are registered and locked in place to align the contact wipers 308 in their exact correct selected positions. This function is not part of the present invention but, briefly stated, is performed by the interoperation of a bail 376 against notches 378 of the plates 280. The notches 378 are aligned with the upper notches of the mark positioned code plates in line with the lower notches of the space positioned code plates so that the five notches are simultaneously engaged by the bail 376. The notches 378 are V-shaped and the bail 376 has a knife edge, hence slightly out-of-line code plates are cammed into place as the register bail 376 engages the notches.

To prevent arcing at the contacts of switch plate 324 when wipers 308 slide into their selected positions, the electric circuit to the common input of plate 324 is held in open condition. After the bail 376 positions and locks the plates 280, the simultaneous circuit is pulsed. A cam on the function shaft 350 is associated with a pair of contacts in series with the energizing circuit to the simultaneous receiving mechanism, and when the lobe of the cam strikes the contacts, they will be closed to pulse the simultaneous code plate circuit.

Simultaneous receiver and solenoid structure Five solenoids arranged in a unitary assembly are em ployed to operate the simultaneous receiving mechanism of this invention and by this arrangement a setof five Y-levers are positioned simultaneously instead of sequentially as in the above described sequential receiver. Having general reference to FIGURE 1 and specific reference to FIGURE 2, an iron housing 386 contains the solenoids. Housing 386 is an assembly of two blocks, an upper block 388 and a lower block 390, fastened together by screws 392 through flanges 394 on the two blocks. Each of the blocks 388 and 390 has five vertical chambers, 396a, b, c, a and e in the upper block, and 398a, b, c, d and e in the lower block, to receive solenoid coils 406 (upper) and 408 (lower). The corresponding upper and lower chambers 396 and 398 are aligned and arrayed in the manner illustrated in FIGURE 13 wherein the vertical axes of the chambers 396, 398 are spaced apart, from front to back, a distance equal to the spacing of a group of Y-lever setting elements 452 which are disposed directly below the solenoid housing 386. The spacing of the axes of the chambers 396, 398 in the other direction places two of them, the axes of chambers 396b and 396d, on the right of the center line of the housing 388 and three of them, the axes of chambers 396a, 396a and 396e, on the left of the center line. Upper and lower chambers 396 and 398 are bored from the abutting ends of the blocks 388 and 390 and terminate a short distance from the outside ends of the blocks. Smaller coaxial threaded holes 400 and 402 (FIGURE 2) connect the ends of the respective chambers 396 and 398 to the outside ends of the housing 388.

Sandwiched and clamped between the two blocks 388 and 390 is an iron or mild steel plate 404 with holes drilled in it to align with the associated chambers 396, 398 of the housing 386. These holes are slightly smaller in diameter than the chambers 396, 398, providing a slight shoulder at the inner end of each chamber portion 396 and 398, for a reason which will presently become apparent.

The assembled receiver solenoid unit contains the following elements within each chamber as illustrated by the cross-sectional view of the one chamber seen in FIGURE 2. The two solenoid coils 406 and 408, wound on sleeve cores 409, made of insulating material, are held snugly between the ends of the respective upper and lower portions 396 and 398 of each solenoid chamber and the aforementioned shoulder, provided by the mid-plate 404, by spring washers 410 and 412. Passing through the sleeve cores 409 of the coils 406 and 408 and through the associated hole in the mid-plate 404 is a non-ferrous metallic sleeve 414 within which an iron or mild steel plunger 416 is disposed with a freely slidable fit. Each plunger 416 has conical ends 418 and 419 and its lower end 419 has an axial bore within which the end of a wire 420 is press fitted. Plungers 416 are free to independently move up and down within the cylinders 414 and are limited in their travel by steel end plugs 422 and 424. Plugs 422 and 424 are identical except for a bore through the axis of each of the lower plugs 424 through which the aforementioned wires 420 project. Each of plugs 422 and 424 has a threaded portion 426 to mate with the threaded holes 400 and 402 at the end of the upper and lower cylinders, and a smaller inner cylindrical end 428. The inner ends 428 of upper plugs 422 have conical recesses 430 to mate with the conical plunger tips 418 and the ends 428 of lower plugs 424, a frusto-conical recess 431 to mate with the lower tips 419 of plungers 416. Each plug 422 and 424 has an outer hexagonal head 432 for tool engagement, and each has a lock nut 434 threaded on its threaded portion 426. Plugs 422 and 424 are turned into the holes 400 and 402 a distance which will allow between inch to 1 inch longitudinal movement of the associated plungers 416 within cylinders 414. The reason for variations in plunger movement will be later described. When the proper amount of movement of each plunger has been set, the lock nuts 434 are turned down against the housing 386 to secure the plugs'.

Centrally located in upper block 388 is a longitudinal through bore 436 aligned with a centrally located hole (not shown) in the plate 404. Channels 440 and 442 (FIGURE 2) in the inside faces of the blocks 388 and 390 (also shown dotted in FIGURE 3) connect each solenoid chamber with the central bore 436. In the assembled solenoid block these channels provide passages to enable the wires from the ten solenoid coils 406 and 408 to be led through the central bore 436 to outside connections.

Magnetic detent of the solenoid plungers will be described with reference to a schematic magnetic circuit of the above described solenoid group shown in FIGURE 4. The plunger 416 is illustrated in its lower position which is the space position for this particular solenoid. The lower convex conical tip 419 of the plunger is held against the concave conical end 431 of the lower plug 424 due to magnetization of the steel plug 424. The polarization of this magnetized plug 424, as shown, is with the South pole at the top and is due to residual magnetism from a previous space pulse to the illustrated lower coil 408. The flux lines due to this permanent magnet (plug 424) are shown by the light dotted lines indicated by the numeral 444. As may be seen, most of this flux flows through the mid-plate 404 to complete the circuit, but some of the flux flows up the blocks 390, 388, through the top plug 422, across the air gap 446 and back down through the plunger 416. This latter flux is indicated by the numeral 448. As shown by this diagram, the plunger 416 will be permanently held against the lower plug 424. There is a slight attractive force between the upper tip 418 of the plunger 416, and the end 43% of the upper plug 422, .but as there is a large air gap at the upper end, the attraction is relatively slight and can be ignored.

When the mark coil 4% at the top of the solenoid is pulsed, aswas explained earlier, there isa magnetic flux circuit caused to flow as indicated by the heavy dotted lines 45% at the left side of the diagram. Due to the direction of the current pulse in this top coil 4%, the upper tip 418 of the plunger 416 will become a North pole and the lower tip 419 will become a South pole. As the end 431 of the lower plug 424 is also a South pole, the two poles will repel one another to release the plunger 416 from the magnetic locking effect of bottom magnetized plug 424. At the same instant that the lower plug 424 releases the plunger, the magnetic field created by flow of current in the coil 4% causes the plunger 416 to tend to center itself in the upper coil 4% and it is snapped up into mark position with its upper tip 418 against the conical end 439 of the top plug 422.

The polarity of upper plug 422 is changed by the mag netic flux created by the current flowing in the top coil 4% -and its conical end 430 thus becomes a South pole to attract and magnetically hold the plunger in this upper position. Due to the fact that the end plugs 422 and 424 are of highly magnetically retentive material, they are slower to respond to changes in polarity than is the magnetic flux circuit and always lag behind. When the current flows through the windings of the coil 466, the flux indicated at 451 causes the lower plunger tip 419 to become a South pole and also causes the end 431 of the bottom plug to' become a North pole. However, the lag mentioned above enables the two parts 419 and 431 to be repelled before the end 431 of lower plug 424 has its polarity changed.

Thus there has been disclosed and described a solenoid plunger which may be driven one way or the other by alternately energized coils 4G6 and 40S and which will always be magnetically locked in its setposition when the coils are dc-energized.

Referring now to FIGURE 2, directly beneath the simultaneous solenoid receiver assembly described above, is a group of five Y-shaped levers 452 pivoted on a post 454 and having a slight turning motion one way or the other which is limited by a stop post 456 coacting with the sides of a slot 453 in each Y-lever. The stop post 456 is directly over the Y-levers pivot post 454 and the slots 458 are slightly wider than the diameter of the stop post 456. Clockwise rotation of a Y-lever is a result of a mark signal and counterclockwise rotation of a Y-lever is a result of a space signal. These five Y-levers 452 are somewhat similar in appearance to the five Y-levers 2480f the sequential receiver and serve the same purpose. Each Y-lever 452 has three arms, a right-hand arm 466 and two left-hand arms 462 and 464. Movement of the Y-levers 452 is effected through their attachment to associated onesof the solenoid plunger wires 42!) projecting through the bottom of the simultaneous .receiver housing 386. The front Y-lever has a Wire 4261: attached to a post 466 at the left of the pivot 454 and is associated with the first element or bit of the Baudot. code. The second Y-lever has the wire 42% attached to a post at the right of the pivot and is associated with the second element of the code. The third Y-lever has the wire 42% attached at thetleft of the pivot 454 and away from the pivot a distance double that of the first wire. The fourth Y-lever has the wire 429d attached at the right of the pivot and away from the pivot a distance double that of the wire 42%. The fifth Y-lever has its wire 42tie attached to the left of the pivot and directly behind the post 456 on the first Y-lever. The plungers associated with wires 429a, 4200 and 4262 move down when their mark solenoids are pulsed and upwhen their space solenoids are pulsed. The plungers associated with wires 42911 and 420d move up when their mark solenoids are pulsed and down when their space solenoids are pulsed.

With the described arrangement of the wire connections to the Y-levers, it is necessary that the solenoid plungers 4160 and 416d within the solenoid receiver housing 336 move twice as far to setthe third and fourth Y- levers as toset the first, second and fifth levers due to the greater distance of the wire attachment from the pivot 454. This difference in movement of the plungers 416 is adjusted by the screw plugs 422 and 424 as was previously explained. The forces necessary to turn the Y-levers are about equal regardless of the greater movement of two of the plungers due to the fact that the two that have to move the farthest are also farther from the pivot 454 so that a greater leverv action is available for the turning of these latter two levers.

Referring again to FIGURE 1, the operations of the simultaneous receiving and translating mechanism subsequent to positioning of Y-levers 452 will now be briefly described.

When the five mark or space circuits set up by code plates 23% are pulsed by the pulsing cam on the function shaft 350, associated ones of the mark or space solenoids within the solenoid receiver housing 386 are energized and magnetically locked to simultaneously move and retain the five Y-levers 452 to desired clockwise or counterclockwise positions; clockwise for marking impulses and counterclockwise for spacing impulses. A second transfer lever 46% for transferring settings of Y-levers 452 is fixed on the end of a shaft 470 and, with shaft 479, can turn clockwise a slight amount under the biasing force of a spring 472.. This transfer lever 468 is latched in cocked condition against the force of spring 472. Release of transfer lever 468' is accomplished by energizing an electromagnet (not shown) which attracts a latching armature which engages an end of a latch lever fixed to the second transfer lever shaft 470. When the release magnet is energized, its armature pulls up and releases the latch lever which in turn permits the transfer lever 468 at the other end of the shaft 470 -to turn under bias of spring 4'72. I

Mounted on the end of an arm 473 of the second transfer lever 468 is a post 4% which pivotally mounts five T-levers 4% (only one being shown), identical to the T-levers 286 previously described for the sequential receiver. When transfer lever 468 is released, the T levers 4% are moved forward against the simultaneously positioned Y-levers 452 and one or the other of the arms 492 or 494 of the T-levers 490 will strike one or the other of the arms 462 or 464 of the Y-levers 452 to turn the T-levers in clockwise or counterclockwise directions. Clockwise rotation of a T-lever is the result of a space signal and counterclockwise rotation is the result of a. mark signal.

The start or latch electromagnet which releases the second transfer lever 463, as described above, is controlled through switch contacts by a cam on the function shaft 350, the switch contacts being closed at approximately the same time as the aforementioned contacts are closed to pulse the solenoids in the simultaneous receiver. Therefore, at the same time the solenoids within the simultaneous receiver are energized to effect the set ting of the simultaneous Y-levers 452:, the electromagnet is energized to effect release of the transfer lever 468. Electromagnet response is made slower than that of the solenoids so the Y-levers will always be completely set before the T-levers 490 strike them. This delay can be accomplished in any of a number of known ways and is not part of this invention, it merely being noted that the Y-levers 452 must be completely set before the T-levers 490 are moved into engagement therewith.

Each T-lever 490 has a tip 498 which engages a notch 502 in an arm 504 of a code device, as for example, a permutation ring 500, one being shown in FIGURE 1. There are five of these rings 5% and when they are rotated to clockwise and counterclockwise positions by the action of T-lever's 490 turning in counterclockwise and clockwise directions, one of a plurality (32 in this embodiment) of stop bars 506 will be sprung into a channel of lined-up notches 508 in the five rings. Once one of the 32 stop bars 506 has been selected by dropping into the aligned notches 508, the T-levers 490 may be disengaged from the Y-levers 452 to free the latter for a new selection. The restoring of the T-levers 409 to a position out of engagement with the Y-levers is accomplished in a manner similar to that used in restoring of the T-levers 286 of the sequential selector. A cam 510 at the end of a second function shaft 512 cooperates with a roller 514 at the end of an arm on the transfer lever 468. When the transfer lever 468 is released, its pivotal movement swings roller 514 against the flat side of cam 510 and subsequent rotation of earn 510 causes the transfer lever 468 to be turned counterclockwise a distance far enough to permit its latch lever at the opposite end of the transfer lever shaft 470 to become latched.

Rotation of the second function shaft 512 to effect the above described restoration of the transfer lever is accomplished by mechanism fully described in parent application Serial No. 628,110.

A number of machine operations are performed as a result of rotation of the second function shaft 512, one of which is the positioning of a type selecting shaft 530. This mechanical operation is fully described in other applications, e.g., parent application Serial No. 628,110 and is not necessary for an understanding of the solenoid structure of this invention.

In the foregoing description and drawings, new sole noid construction and operation has been disclosed to enable a high speed selection of one or two positions by electrical impulse signals of minute duration. The solenoid plunger position is maintained by a novel magnetic detent action.

The invention may be embodied in other specific forms Without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. An electromagnetic device in combination with a simultaneous code signal combination receiving mechanism, comprising: a unitary multiple two-position solenoid plunger mechanism comprising a plurality of reciprocable two-position plungers, at least two control circuit means with solenoid coils for each plunger enabling selective independent positioning of all said plungers in each of their two positions, and means disposed adjacent the two ends of each plunger provide magnetic detents for holding all of said plungers in each of their selected positions.

2. A unitary two position multiple solenoid plunger mechanism including: a structurally integral block housing with a plurality of bores; solenoid coils in each of said bores; plungers in said solenoid coils; at least two control circuits for each plunger including the said coils associated therewith and enabling independent positioning of all plungers; and magnetic field retentive plugs disposed in said bores adjacent the ends of said plungers providing magnetic detents for holding all of said plungers in each of their selected positions.

3. A unitary two position solenoid plunger mechanism comprising: a block means having a hole therethrough; two solenoid coils in said hole, one at each end thereof; a solenoid plunger slidable within said coils; an end plug in each end of said hole, each plug adapted to be engaged by the adjacent end of said plunger when an appropriate coil is energized and the plunger moved to abut an end plug; a hole through one end plug; a member projecting through the hole in said one plug and fixed to the adjacent end of said plunger; said plugs being made of a magnetically retentive material whereby the flux path of a solenoid coil causing associated plunger movement to an end of said hole will magnetize said plunger and abutted plug with a predetermined polarity to provide a magnetic detent retaining said plunger abutted against said plug.

4. A unitary two position solenoid plunger mechanism as defined in claim 3 wherein the ends of said plungers are convex and the ends of said plugs abutted by said plungers are complementarily concave relative to the convex plunger ends.

5. A simultaneous electrical code signal combination receiving and translating mechanism comprising: a support; a plurality of two-position levers pivotally disposed on said support on a common axis in side-by-side relation and spaced slightly from each other; a unitary multiple solenoid structure having a multi-wire operating circuit on said support including a housing comprising at least one structurally integral block made from magnetically conductive material and having a plurality of parallel bores therethrough, a portion of said circuit including a plurality of solenoid coils, one coil being disposed in each of said plurality of bores, and a plurality of solenoid plungers, each plunger projecting into a said coil coaxial with the associated bore and independently movable in accord with electric code signal combinations received in said multi-wire circuit in parallel paths transverse to said lever axis with a plunger aligned with each of said levers; means connecting aligned plungers and levers to enable lever movement as a result of plunger movement; and means connected to said housing coacting with said plungers to delimit end positions of plunger movement and to provide detent action for maintaining plungers and levers in whichever position they are moved by received code signals.

6. A simultaneous electrical code signal combination receiving and translating mechanism as defined in claim 5 wherein said means to provide detent action comprise plugs made of magnetically retentive material, one plug being disposed in said solenoid structure at the limit positions of travel of each said plunger.

7. An electromagnetic device comprising: a cylindrical plug core of magnetic material having a high degree of magnetic retentivity and initially possessing a given remanent flux; a two position reciprocal iron plunger core; a solenoid coil wound about portions of both said cores and so positioned that when said plunger core is in a first position the air gap between said cores is placed approximate the middle of said solenoid coil, means to energize said coil in one direction to move said plunger core to a second position in proximity to said plug core, said remanent flux in said plug core being intensified during energization of said coil and sufficient to retain said iron plunger core in said second position, and means to move said iron plunger core away from said plug core to said first position and to maintain said plunger core in said first position against the force of the remanent flux of said plug core.

8. An electromagnetic device as defined in claim 7 wherein said plug core has a bore formed axially therein, and a rod is axially secured in said plunger and projects through said plug bore.

9. A unitary solenoid device comprising: block means made from magnetically conductive material with a hole passing therethrough; two solenoid coils disposed substantially coaxially in said hole, one at each end thereof; a solenoid plunger slidable within said coils; a partition means of magnetically conductive material between said coils contacting said block means and fitted around said plunger with a close but free sliding relative disposition; and end plug made from magnetically retentive material disposed in each end of said hole, the distance between said plugs being greater than the length of said plunger and'eac'n plug adapted to be abutted by the adjacent'end of saidplunger when a selectedone of said plunger when a selected one of said two coils is energized'and the plunger is accordingly shifted intoengagement with an end plug; a passage throughone of said end plugs; a member projecting throughzthe passage in said one end plug and fixed'to the adjacent end of said plunger; said arrangement of block means, coils, partition means, plunger and end plugs constituting a structural and functional relationship wherein the major portionof the flux path generated by the energizing ofione. of said solenoid coils and causing :the plunger to move to abut a first of said plugs at an associated end of said hole, passes through said partition means to bypass theother plug and will magnetize said plunger and said first plug'with a predetermined first polarity to provide a magnetic detent force retaining said plunger abutted against said first plug, and When the other of said solenoid coils is energized,-.thet.reversedfiux pathfromisaid other coil will cause the: plunger to move to the opposite end and abut said other plug: andthe major portion of such reversed flux path will pass through said partition means to by-pass said firstplug and will reversely. magnetize the plunger andsaidiother plug with a polarity. opposite to said first polarity to provide a magnetic detent force retainingvsaid plunger ahuttedagainst said other plug.

10. A unitary solenoid device as defined in claim 9 wherein said partition means is an aper-tured metal plate andsaid block. meansincludes twoimetal blocks each having a planar mounting surface and at least one bore therein normal to said planar surface, said blocks are disposed with their planar mounting surfaces on opposite blocks and saidplate together as a unit.

'11. A unitary solenoid device as defined in claim 9,

wherein said block means are-made with aplurality of holes therethrough and arranged so the axes of said holes are parallel, two solenoidcoils' are disposed in each hole, one at each end, asolenoid plunger is axially slidable in each hole :within the associated two coils, said'partition meansis apertured in a plurality of locations to fit around each of said plungers with a close but free sliding relative disposition, magnetically retentive end plugs are located in each end of each of said holes, one end plug in each of said holes has a passage extending therethrough, and a plurality of members are provided so that an individual one of said members connects to one end of an associated plunger and projects through the associated said end plug with a passage. I

References Cited "in the file of this patent UNITED STATES PATENTS 707,967 Griscom Aug. 26, 1902 822,223 Richards May 29, 1906 1,485,750' Wolfe et al Mar. 4, 1924 1,918,798 Churcher July 18, 1933 2,046,272 Larson et'al. June 30,1936 2,057,380 Keefe Oct. 13, 1936 2,836,676 Wirth May 27, 1958 2,935,656 Baker May 3, 1960 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,170,988 February 23, 1965 David C. Sherrick It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 11, line 2, strike out "a selected one of said plunger when Signed and sealed this 3rd day of August 1965.

(SEAL) litlest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,170,988 February 23, 1965 David C. Sherrick It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 11, line 2, strike out "a selected one of said plunger when Signed and sealed this 3rd day of August 1965.

(SEAL) Altest:

ERNEST W. SWIDER- EDWARD J. BRENNER A-ttesting Officer Commissioner of Patents 

5. A SIMULTANEOUS ELECTRICAL CODE SIGNAL COMBINATION RECEIVING AND TRANSLATING MECHANISM COMPRISING: A SUPPORT; A PLURALITY OF TWO-POSITION LEVERS PIVOTALLY DISPOSED ON SAID SUPPORT ON A COMMON AXIS IN SIDE-BY-SIDE RELATION AND SPACED SLIGHTLY FROM EACH OTHER; A UNITARY MULTIPLE SOLENOID STRUCTURE HAVING A MULTI-WIRE OPERATING CIRCUIT ON SAID SUPPORT INCLUDING A HOUSING COMPRISING AT LEAST ONE STRUCTURALLY INTEGRAL BLOCK MADE FROM MAGNETICALLY CONDUCTIVE MATERIAL AND HAVING A PLURALITY OF PARALLEL BORES THERETHROUGH, A PORTION OF SAID CIRCUIT INCLUDING A PLURALITY OF SOLENOID COILS, ONE COIL BEING DISPOSED IN EACH OF SAID PLURALITY OF BORES, AND A PLURALITY OF SOLENOID PLUNGERS, EACH PLUNGER PROJECTING INTO A SAID COIL COAXIAL WITH THE ASSOCIATED BORE AND INDEPENDENTLY MOVABLE IN ACCORD WITH ELECTRIC CODE SIGNAL COMBINATIONS RECEIVED IN SAID MULTI-WIRE CIRCUIT IN PARALLEL PATH TRANSVERSE TO SAID LEVER AXIS WITH A PLUNGER ALIGNED WITH EACH OF SAID LEVERS; MEANS CONNECTING ALIGNED PLUNGERS AND LEVERS TO ENABLE LEVER MOVEMENT AS A RESULT OF PLUNGERS MOVEMENT; AND MEANS CONNECTED TO SAID HOUSING COACTING WITH SAID PLUNGERS TO DELIMIT END POSITIONS OF PLUNGER MOVEMENT AND TO PROVIDE DETENT ACTION FOR MAINTAINING PLUNGERS AND LEVERS IN WHICH EVER POSITION THEY ARE MOVED BY RECEIVED CODE SIGNALS. 